Early in his presidency, the president and his advisors were wary of making any comments about the stock market or the jobs numbers that could be seen as too upbeat—even when good numbers were released. They worried that booster-ish comments about the turnaround would seem out of step with the economic pain millions of Americans were feeling. So the official White House line was often some variation of "good, but could be better."

That's all changed.

In recent weeks, Obama has begun to use words like "booming" to describe the economy, and to cite "record" growth in various areas. It's a rhetorical shift driven by a political calculus in an election year—and a presidential timing calculus: Obama knows he has more of his presidency in the rear view mirror than ahead. And with GDP expanding at a robust 4 percent annual rate as of last week, his aides are confident that the strong numbers will continue, making it less of a risk to tout success now.

"They feel more comfortable," said a former Obama Administration official. "The real release was when they saw that four handle on GDP." Steady gains have changed the mood inside the White House complex, the former official said. "The fear in the past was even if the overall numbers were good there were still a lot of people feeling pain, so it seemed discordant. But now people are starting to feel a little better about their own personal situation."

The shift is pronounced. In an interview with The Economist released over the weekend, Obama made a full-throated argument for his economic legacy that came without the hedges and caveats he has used in past years. "Let's look at the facts," Obama said. "Since I have come into office, there's almost no economic metric by which you couldn't say that the U.S. economy is better and that corporate bottom lines are better. None."

The president has even started talking about the stock market—an often volatile gauge the White House has shied away from in the past. "The stock market is booming," Obama said in a speech in Kansas City, Missouri, on July 30. And in an interview with CNBC's Steve Liesman on July 24, Obama pointed to the good economic news since he's come to office: "I don't have to tell you about the stock market and where that's gone," the president said. "Corporate profits: record highs."

Obama delivered a similarly upbeat verdict in the White House press briefing room on Friday afternoon. "The economy grew at a strong pace in the spring," he said. "Companies are investing. Consumers are spending. American manufacturing, energy, technology, autos—all are booming."

Contrast that bullish language with the far more cautious comments the president made in a weekly radio address almost exactly a year earlier: "Over the past four and a half years, we've fought our way back from the worst recession of our lifetimes and begun to lay a foundation for stronger, more durable economic growth," the president said on Aug. 3, 2013. "But as any middle-class family will tell you, we're not where we need to be yet."

Business advocates in Washington say they've noticed the shift. "He's starting to get into legacy mode," said one business industry leader.

It's a little early for legacy comparisons, but if the numbers hold, Obama will be one of the best presidents for stock market performance in the post World War II era, but he's a long way from the top. So far in Obama's term, the S+P 500 index is up 126.65 percent, as of Monday. But three other presidents associated with economic booms saw even better results. Ronald Reagan presided over a 160.31 percent increase in the S+P. Bill Clinton saw S+P gains of 163.49 percent. And Dwight Eisenhower saw a whopping 169.28 percent jump in the index.

Still, the rhetorical transition from "not where we need to be yet" to "booming" can be difficult to make, even for the people closest to the president.

On Friday, White House Council of Economic Advisers Chair Jason Furman appeared before cameras to talk about that day's jobs number, which showed 209,000 new jobs created, for the sixth consecutive month of 200,000-plus jobs gains. But Furman seemed stuck on the old Obama talking points, just hours before Obama would go to the briefing room and declare sectors of the US economy were booming.

"We'd like to see more people coming back into the labor force, too," Furman said. "So we have further to go. We're certainly not all the way there yet, but we keep moving in the right direction